Recently, a high-speed broadband service such as a Fiber To The Home (FTTH) system and cloud computing for general users have been spreading. Accordingly, information technology (IT) equipment such as a server, a router, or a switch in a data center is rapidly increasing in speed and capacity. Under the circumstances, an electric interconnect which has traditionally been used in IT equipment or between pieces of IT equipment is demanded to have transmission capacity of 10 to 25 Gbps or more per channel. However, the limit of speed of the electric interconnect has become a problem, for reasons such as a malfunction of equipment caused by generation of high frequency noise due to increased speed, and a need for a new waveform-regulating element and the like, arising from generation of transmission loss of a high frequency signal. Meanwhile, light is non-inductive, which does not cause a noise or a crosstalk to generate among a plurality of optical signal transmission lines arranged in parallel. Additionally, light is easy to control, as a modulation frequency thereof is unrelated to reflection and loss. Therefore, if a multichannel parallel and high-speed signal transmission line becomes fiber-optic in equipment or between pieces of equipment, a high frequency signal of 10 Gbps or more is able to be propagated with low loss. This reduces the number of wiring lines, and avoids the need for the abovementioned measures for high frequency signals. For these reasons, optical transmission is a promising solution. Furthermore, video equipments such as a video camera, and in consumer equipments such as a personal computer (PC) or a mobile phone, as well as in a router and a switch mentioned above, video signal transmission between a monitor and a terminal is demanded to increase in speed and capacity, with the future development of high-definition images. In addition, the problem of a measure for a signal delay or a noise in conventional electric wiring will become conspicuous. Therefore, it is effective to convert a signal transmission line to an optical fiber.
To achieve a high-speed optical wiring system described above, and to apply such system in equipment or between pieces of equipment, it is necessary to obtain an optical module or an optical circuit which are manufactured in a low cost way, but are excellent in performance, compactness and integration, and component packaging. Then, there is proposed a small-sized and high-speed optical module having a substrate on which an optical component and an optical fiber connector are integrally mounted.
PTL 1 discloses, as an example of a conventional form of an optical module applicable to an optical wiring system, a package configuration of a small integrated optical module having a package substrate on which an optical element array, an integrated circuit, and an optical connector are mounted. In this example, for the purpose of miniaturizing and highly densifying the optical module, an optical connector is mounted three-dimensionally on a substrate on which a multichannel optical element array and an integrated circuit are packaged. In addition, a positioning pin placed on the substrate is inserted into a positioning hole formed in an optical connector, whereby the optical element array and an optical fiber array are optically connected in a simple fashion.